This invention relates particularly to breathing face masks which seal against the face of a user and exclude the ambient environment from those portions of the face which are confined by the mask.
It is important that a face mask properly fit the face of the wearer. The need for a good seal is self-evident. However, comfort in the fit of the mask to the face also is a significant factor because if the mask is not comfortable to wear it will bother and distract the user.
Generally, face masks are not custom made. Instead, they are made in only a very limited number of shapes and sizes, intended for use with a wide variety of facial shapes and sizes. The wide range in shape and size of the human face makes it difficult to provide a mask which will comfortably fit a variety of users, particularly with masks designed to provide wide angle vision.
U.S. Pat. No. 3,545,436, assigned to the Assignee of this application, discloses a useful face mask seal arrangement in which a floating seal is suspended from a relatively rigid mask body in a manner to be conformable in sealing relation to the face of a user independently of the mask body. As the mask is positioned against the face a connecting hinge web resiliently yields and urges the floating seal against the face.
In some situations, for example when the mask has a relatively flat upper edge curvature to comfortably fit beneath a fireman's helmet, it is desireable to reinforce the sealing action provided by such connecting hinge web as it resiliently yields and buckles.